1. Field of the Invention
The invention relates to a circuit for filtering narrow pulse and compensating wide pulse.
2. Description of the Related Art
As shown in FIG. 1, a typical permanent magnet synchronous motor controller includes a PWM signal generator, an inverter unit, and a motor body (M). The motor body (M) includes a permanent magnet rotor, a stator, and windings (U, V, and W). The PWM signal generator can adopt a micro controller unit (MCU) or a special integrated circuit chip IC, and generate pulse signals of a certain width, so that the insulated gate bipolar transistors IGBT (Q1, Q2, Q3, Q4, Q5, and Q6) of the inverter unit are conducted by turns, and the windings (U, V, and W) are powered on by turns.
During the treatment process of the conventional motor controller, driving signals used for controlling the IGBT and calculated through the PWM signal generator (i.e., micro controller unit (MCU)) under the action of modulation and demodulation from software include narrow pulses. The narrow pulses have negative effects on the IGBT (Insulated Gate Bipolar Transistor). As shown in FIG. 2, before the PWM signal generator generates normal drive pulses B, a plurality of narrow pulses will be generated. These narrow pulses A will be closed immediately before the complete opening of the IGBT, the IGBT will be overheated, thus the service life will be affected, the IGBT will be destroyed after a long time of use, even the IGBT will be burned out, and the negative impact to motor control will be caused. Therefore, the modulated pulses are required to be treated.